Field
This disclosure relates generally to magnetic random access memory (MRAM), and more specifically, to MRAMS utilizing cells having multiple transistors and a magnetic tunnel junction (MTJ) element.
Related Art
One type of emerging memory is a Spin-Transfer-Torque MRAM (STT-MRAM) utilizing a Magnetic Tunnel Junction (MTJ). STT-MRAM memories are being considered to rival FLASH memories and other non-volatile memories. To be commercially practical, however, these memories must have comparable memory density to current memory technologies, be scalable for future generations, operate at low voltages, have low power consumption, and have competitive read/write speeds.
Storing data is accomplished by passing current through an MTJ element, causing it to be either in a low resistive state or a high resistive state. Reading data stored in the memory is accomplished by sensing differences in resistance in the MTJ element between the two states. Typically, the stored state of a memory cell can be determined by comparing the cell state to that of a reference cell. However, the difference in resistance between a high state and a low state can be very small, requiring a sense amplifier with high sensitivity. Therefore, there is a need for a sensing method having increased sensitivity for an improved read operation.